White Space Beamforming Exclusion Zones
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Solution Overview
Problem
Existing methods for utilizing white spaces in wireless communications often result in static spectrum utilization and potential interference with licensed users, as they rely on all-or-nothing approaches to detect and avoid incumbent transmissions, limiting the efficient use of unused spectrum.
Innovation Solution
The method involves generating correlation results from detected transmissions to identify erroneous indications of incumbent signals and using beamforming parameters to adjust transmission patterns, ensuring non-interference by excluding areas where incumbent signals are detected, thereby maximizing white space spectrum availability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If received power detection is used to identify white spaces, then system cost is reduced, but measurement precision deteriorates leading to false detection of incumbent signals
Solution Approach 1:
A correlation detection mechanism is introduced as an intermediary layer between the simple power detector and the final detection decision. The mechanism correlates detected signals with known incumbent signal characteristics (signatures) to verify whether a detected power level actually corresponds to an incumbent transmission, thereby eliminating false alarms while maintaining the simplicity and low cost of power-based detection.
2Ease of operation
If all-or-nothing spectrum activation is used, then interference avoidance is simplified, but spectrum utilization efficiency deteriorates
Solution Approach 1:
The system applies different operational states to different frequency bands within the same geographical area. Instead of uniformly activating or deactivating all frequencies, the system independently controls each frequency band based on local detection results, allowing some bands to be active while others remain inactive, thereby maximizing overall spectrum utilization while maintaining interference avoidance.
Solution Approach 2:
The frequency spectrum is segmented into multiple independently controllable bands. Each band can be detected, evaluated, and activated or deactivated separately based on the presence or absence of incumbent signals, allowing fine-grained control over spectrum usage rather than treating the entire spectrum as a single unit.
3Measurement precision
If signature detectors are used to detect incumbent transmissions, then measurement precision is improved, but device complexity increases and cost rises
Solution Approach 1:
The system implements a two-stage detection approach where a simple power threshold test is performed first as a partial detection mechanism. Only when this initial test indicates potential incumbent presence does the system engage the more complex correlation-based verification. This partial application of complex detection minimizes overall system complexity while maintaining high detection accuracy when needed.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for dynamic and efficient use of white space spectrum while minimizing interference with incumbent equipment, enhancing network capacity and user experience by adaptively modifying beamforming parameters based on real-time transmission activity.
Implementation Method 1
a sensor present in the mobile communication system or in another transmitter, configured to detect transmissions from the mobile communication system or from the other transmitter
Implementation Method 2
ascertaining beamforming parameters to transmit signals from the mobile communication system throughout the predefined geographical area except for any portion of the predefined geographical area located on a far side of an exclusion boundary
Data Source
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AI summary
Mobile communication system equipment avoids interfering with another transmitter's operation. Sensing information indicating whether the other transmitter's signal has been detected is received from remote sensors, wherein each of the remote sensors is situated at a respective one of two or more sensor locations. The sensing information and information about the sensor locations is used to ascertain one or more exclusion boundaries needed to avoid interfering with the other transmitter's use of the spectral resource. Beamforming parameters are ascertained that will enable the main node to transmit within one or more predefined geographical areas except for any portion of a predefined area located on a far side of the one or more exclusion boundaries. Two or more adjusted signals are produced as a function of the beamforming parameters and one or more signals to be transmitted. The adjusted signals are transmitted from respective ones of two or more antennas.